This paper describes a prototype power delivery system developed for high voltage electronic current transformer （ECT） that uses laser light to transfer power to and communicates with the primary converter. The desi...This paper describes a prototype power delivery system developed for high voltage electronic current transformer （ECT） that uses laser light to transfer power to and communicates with the primary converter. The design is based on optical-to-electrical power converters, solid-state diode lasers and optical fibers. Command signals are transmitted via the same up-fiber used to send power from secondary power supply to primary converter. The upward data transmission is completed during the brief interruption of power delivery without affecting steady power-supply. A simple comparator added to the primary converter can take the command data. Experimental results show that the fibers can provide reliable up-link for data transmission at 200 kb/s from the secondary to the primary converter. Based on the delivery system, the secondary converter can control three auxiliary channels to provide additional information. These monitoring channels are used in a time-multiplexing mode to provide information about the operation temperature, voltage and current at the remote unit for monitoring the ECT. This preventive maintenance or built-in test can increase reliability by giving early warning for necessary maintenance request.展开更多
基于Pockels效应的光学电压传感器(Optical Voltage Transducer,OVT),运行中不可避免地存在震动、元器件连接的老化与热胀冷缩等问题,导致光学器件的相互位置产生偏移,进而影响电光晶体的内电场分布。文中以基于会聚偏光干涉原理的110 ...基于Pockels效应的光学电压传感器(Optical Voltage Transducer,OVT),运行中不可避免地存在震动、元器件连接的老化与热胀冷缩等问题,导致光学器件的相互位置产生偏移,进而影响电光晶体的内电场分布。文中以基于会聚偏光干涉原理的110 k V纵向调制的OVT为例,进行了仿真分析与实验研究,发现当入射光发生±0.5°的偏移或电光晶体发生±1°的偏移时,分别引入约0.107%和0.124%的电场积分误差。由于OVT必须满足0.2%的准确度要求,上述影响不容忽视。为此提出了介质包裹法,将Al2O3陶瓷包裹在电光晶体外部,使电场积分误差分别降低至0.001%和0.003%。实验与应用的情况表明,介质包裹法简单、实用、有效。展开更多
We present a novel efficient approach in calculating induced transmembrane voltage（ITV） on cells based on transformation optics. As cell membrane is much thinner than the dimension of a typical cell, discretizing th...We present a novel efficient approach in calculating induced transmembrane voltage（ITV） on cells based on transformation optics. As cell membrane is much thinner than the dimension of a typical cell, discretizing the membrane needs numerous meshes. Using an anisotropic medium based on transformation optics, the thickness of the membrane can be exaggerated by at least one order, which eliminates rigorous mesh refinement and reduces unknowns greatly. The accuracy and efficiency of the proposed method are verified by a cylindrical cell model. Moreover, the influence on ITV with bound water（BW） layers is also studied. The results show that when cells are exposed to nanosecond electric field, BW layers should be rigorously considered in calculating ITV.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No.50447006）
文摘This paper describes a prototype power delivery system developed for high voltage electronic current transformer （ECT） that uses laser light to transfer power to and communicates with the primary converter. The design is based on optical-to-electrical power converters, solid-state diode lasers and optical fibers. Command signals are transmitted via the same up-fiber used to send power from secondary power supply to primary converter. The upward data transmission is completed during the brief interruption of power delivery without affecting steady power-supply. A simple comparator added to the primary converter can take the command data. Experimental results show that the fibers can provide reliable up-link for data transmission at 200 kb/s from the secondary to the primary converter. Based on the delivery system, the secondary converter can control three auxiliary channels to provide additional information. These monitoring channels are used in a time-multiplexing mode to provide information about the operation temperature, voltage and current at the remote unit for monitoring the ECT. This preventive maintenance or built-in test can increase reliability by giving early warning for necessary maintenance request.
文摘基于Pockels效应的光学电压传感器(Optical Voltage Transducer,OVT),运行中不可避免地存在震动、元器件连接的老化与热胀冷缩等问题,导致光学器件的相互位置产生偏移,进而影响电光晶体的内电场分布。文中以基于会聚偏光干涉原理的110 k V纵向调制的OVT为例,进行了仿真分析与实验研究,发现当入射光发生±0.5°的偏移或电光晶体发生±1°的偏移时,分别引入约0.107%和0.124%的电场积分误差。由于OVT必须满足0.2%的准确度要求,上述影响不容忽视。为此提出了介质包裹法,将Al2O3陶瓷包裹在电光晶体外部,使电场积分误差分别降低至0.001%和0.003%。实验与应用的情况表明,介质包裹法简单、实用、有效。
基金Project supported by the National Key Basic Research Program of China(Grant Nos.2013CB328900 and 2013CB328905)
文摘We present a novel efficient approach in calculating induced transmembrane voltage（ITV） on cells based on transformation optics. As cell membrane is much thinner than the dimension of a typical cell, discretizing the membrane needs numerous meshes. Using an anisotropic medium based on transformation optics, the thickness of the membrane can be exaggerated by at least one order, which eliminates rigorous mesh refinement and reduces unknowns greatly. The accuracy and efficiency of the proposed method are verified by a cylindrical cell model. Moreover, the influence on ITV with bound water（BW） layers is also studied. The results show that when cells are exposed to nanosecond electric field, BW layers should be rigorously considered in calculating ITV.
